Unfortunately your submission Stringer- Responsive Wordpress Theme isn’t quite ready for ThemeForest and requires significant improvements and changes before it can be resubmitted and reconsidered.

Additionally, we have some extra feedback for you:

Your design has a good start but, as we have high standards, you will need to make some additional improvements in overall aesthetics and aspects such as typography, graphics and spacing.

Try to make your template’s design more unique. Attention to detail and unique graphic styles will help increase your template’s design value and increase its ability to be approved. A unique design will be always a key factor for approval.

At this point, we’re only looking for unique variations of this design: for another one to be approved it would have to have unique touches and features that differentiate it from what’s already available and definitely be of higher quality.

Can I use for example Visual Composer or Revolution Slider in my Wordpress theme which will be sold on themeforest?
Of course I will buy these items with extended license?
Is this really simple as that?